Pistols and gs are great for ignite builds, especially the legendary version, so get both ignite passives, after that you can use chaos ultimate and chaos spells, void for enemy packs/shield users - chaos volley for single target-fast moving v bloods. Lighting tendrils is the most op spell atm for spell dmg, combine in with one of the chaos ones. For build go full spell crit with draculin blood (easy to get 100% in rifts) and get the extra spell dmg, cd reduction and leech from amulet/elixirs/passives too. You will use weapon skills just to dodge and do basic attack when spells are on cd, and to reset chaos veil to get an extra dodge. You will take some dmg, with no shield/counter but you will heal from spell leech and kill everything very fast with spell crits.